The latest blockbuster film may have heart-pounding action, and a dramatic tearjerker may tug on your heartstrings, but for a movie that’s actually good for your heart, check out a comedy.

That’s the conclusion of researchers at the University of Maryland’s School of Medicine, who showed volunteers comedic and dramatic films to gauge the effect of emotions on heart health. In their March 2005 study, the researchers found a medical basis behind the adage that laughter is the best medicine. They linked laughter, for the first time, to the healthy function of blood vessels.

The study included 20 volunteers – 10 men and 10 women. The average age of the study participants was 33 and all of them were healthy non-smokers. During the trial, half of the study subjects viewed a 30-minute segment of a comedy and two days later watched 30 minutes of a war film. The remaining 10 study subjects were subjected to the same movies for the same length of time, but in reverse order.

Healthy response

After watching the comedy, the endothelium – the lining of blood vessel walls – had expanded in 19 of the 20 subjects allowing blood to flow more easily to the heart. Conversely, when they watched the war film, 15 of the 20 subjects developed a potentially unhealthy response, where the lining of the blood vessel walls constricted. Overall, the average blood vessel diameter increased by 22% when people were laughing and decreased 35% when they were stressed.

"The endothelium is the first line in the development of atherosclerosis , or narrowing of the arteries ,” says Dr. Michael Miller, the study’s principal investigator. "It is conceivable that laughing may be important to maintain a healthy endothelium, and reduce the risk of cardiovascular disease.”

While he couldn’t pinpoint the source of laughter’s benefit, speculation includes the movement of the diaphragm muscles, and the stimulation of endorphins – chemicals released by the brain that help produce a sense of pleasure and well-being.

Dr. Miller’s research is a follow-up to his 2000 study that found that a sense of humour could protect you from a heart attack. Some 300 volunteers – 50% of whom were healthy, and 50% who had suffered a heart attack or bypass surgery – were surveyed on their likely emotional response to certain social situations. His research revealed that those with heart disease were 40% less likely to take a lighthearted approach than healthy subjects of the same age.

Get the giggles

Other notable studies are exploring the link between emotion and heart disease. In Canada, Dr. Ken Prkachin of the University of Northern British Columbia found that people with anger management difficulties had sudden, exaggerated increases in blood pressure. Over time, he says, this can cause wear and tear on the blood vessel walls.

Studies like these could have implications for treating and preventing heart disease. "There’s an unacknowledged importance of how our social lives impact our health status,” says Dr. Prkachin. "Now we know that laughter, a social behaviour, is linked to healthy physiological processes.”

In fact, says Dr. Miller, laughter’s effect on the endothelium was similar to the benefit you’d see from aerobic activity – but without the aches and pains.

"We don’t recommend that you laugh and not exercise – but we do recommend that you try to laugh on a regular basis,” says Dr. Miller. "Thirty minutes of exercise three times a week, and 15 minutes of laughter on a daily basis, is probably good for the vascular system.”

To get active, join the thousands of mothers, daughters, families and friends who will be walking to raise awareness and funds to improve the health of women in British Columbia. The Cheerios Heart and Stroke Mother Daughter Walk takes place September 25th at Rathtrevor Beach. Call now to register (888)-754-5274 or visit www.heartandstroke.ca/walk